Expansible abrading tool



May 29, 1934.

,1. E. sms

EXPANSIBLE ABRADING' TOOL Original Filed Oct. 14, 1930 2 Sheets-Sheet l Invenlor 175mm)" EA Allomey May 29, 1934. J. E. SIMS EXPANSIBLE ABRADING .TOOL

2 Sheets-Sheet 2 Original Filed Oct. 14. 1930 lnvenlor VVVYVVK VV 1 I VVVV v//// Egg Allorney Patented May 29, 1934 UNITED STATES EXPANSIBLE ABRADIN G TOOL James E. Sims, Santa Ana,

CaliL, assignor to Joseph Disco, Santa Ana, Calif.

Application October 14, 1930, Serial No. 488,651 Renewed February 7,1934

9 Claims. (01. 51-is4.1)

This invention relates tofan abrading tool and is particularly adaptedfor finishing piston pin holes of internal combustion engines and any other abrading operation that requires precision.

An object of the invention is to provide a tool which is adapted to be attached to a rotating source of power and projected into the opening to be-ground, or may be fixed in a vise and the work rotated. f

Another feature of the invention is to provide a suitable means of anchoring the abrading cloth to the tool to permit the rotation of the tool in either direction without cutting the abrading cloth.

Still anotherfeature of the present invention is to provide for the expansion of the abrading, sleeve to a very fine degree of precision.

Further objects of the invention are to provide an abrading tool of the character referred to'that is strong, compact and durable, thoroughlyreliable for its intended purpose, very simple in its method of assembly, very easy to manipulate,

and comparatively inexpensive to manufacture.

With the foregoing and other objects in view,

the invention consists in the novel combination,

construction and arrangement of parts as will be\ hereinafter more specifically described and illustrated in the accompanying drawings, wherein is disclosed an embodiment of the invention, but

it is to be understood that changes, variations and modifications may be resorted to without departing from the spirit of the claims hereunto appended.

In the drawings, whereinlike reference characters denote corresponding parts throughout the several views:

Fig.- 1' is a side elevation of one form of the abrading tool in assembled relation;- I

Fig. 2 is an elevation, partly in section thereof; Fig. 3 is a radial section, taken substantially on the line 33 of Fig. 2;

Fig. 4 is an end view thereof, without the abrading cloth;

Fig. 5 is a side view of the mandrel; Fig. 6 is a radial section through the mandrel,

- taken substantially on the line 6-6 of Fig. 5;

Fig. 7 is a detailed longitudinal section of the sleeve taken through the slot in the sleeve; and Fig. 8 is an end view of the sleeve removed from the arbor.

Referring to the drawings in detail, A indicates the arbor, on one end of which is a reduced shank 10, the free end of which is formed ,of a polygonal configuration 11, adapted to be received in a socket of a chuck or other holding device, or

is adapted to be placed in the jaws of a vise and the work rotated about the abrading tool of the threaded to receive encircling threaded members as collars or end-stops 21 and- 22. Sleeve S is slotted along its length, a portion of its circumference being removed, sothat it subtends less than 360 degrees. This provides a longitudinal opening and also permits its diameter to be varied. This change in diameter is eiiected by tapering the contacting or supporting and cooperating parts of mandrel and sleeve or of ribs, as 30, interposed between sleeve and mandrel. By tapering any cooperating pair of the parts, say ribs 30 and the support portion or portions of the mandrel 12, the sleeve diameter may be changed by axial movement of the sleeve S. Tapped collars 21 and 22 are spaced apart on the mandrel with sleeve S between them. Obviously, by screwing the collars to force the sleeve axially along the mandrel, the sleeve diameter will be gradually and accurately adjusted, responsive to its elasticity.-

A helical groove 20 is formed in the periphery of mandrel 12 to provide a recess for accumu lated material abraded from different objects worked or any dirt, grit or other substances. By rotation the groove will discharge such accumulations as may be loose in it at one end or the other, depending on the directionof rotation.

Of. course, continuous circumferential contact between sleeve S and mandrel 12 is neither needed nor even desirable, for many obvious mechanical reasons. Hence longitudinal ribs, before referred to, spaced circumferentially, as 30, are interposed between the inner surface of sleeve S and the mandrel 12. These ribs, being tapered along their length, cooperate with tapered supporting zones or portions of the mandrel. The mutual tapering between the, sleeve S and mandrel 12 at or along parts or zones of supporting contact is the specifically required relation, and wherever ribs, as 30, space the inner periphery of the'sleeve S from the mandrel 12, the complementary taper of the two said members at the zones of mutual I III contact is necessary but may be omitted-at such surfaces as are not in contact.

In the drawings the ribs 30 are shown attached to sleeve S, hence the foregoing explanation, as the invention includes simply interposition of ribs between mandrel and sleeve and any suitable complementary taper between the mandrel and the sleeve at such areas as mutually cooperate.

As shown, tapped members 21 and 22 which screw on the threaded ends 15 and 16 respectively of mandrel 12 have each an end formation cooperating with the adjacent sleeve end and serves both to constrict and to move the sleeve.

The previously specified tool is for the purpose of supporting a thin flexible sheet of appropriate material, covered with an abrasive, this being of the general character of emery cloth or a similar kind of material abrading sheet. The tool described is broadly to support such a sheet, so that it is substantially truly cylindrical; which can be easily removed and a fresh sheet substituted for the removed sheet, the operative sheet being stretched around sleeve S and held against relative movement between the supporting sleeve and the abrasive sheet when being used, and the diameter of the abrading surface is adjustable in extremely minute steps, substantially micrometrically. The abrasive sheet, as 31, is wrapped around slotted sleeve S, the longitudinal or axial ends being carried into the longitudinal sleeve slot 27 and there anchored in any suitable manner. One preferred method is to provide a pair of parallel longitudinal slots as 18 and 19 in the mandrel 12, spaced circumferentially a few degrees apart, and to push each'longitudinal edge or" the abrasive material into its appropriate slot, in which it may be held by any suitable means, as plain friction, cementing or otherwise. Usually the longitudinal edges of the abrasive sheet are drawn endwise into the slots 18 and 19 and withdrawn in a similar axial movement. By this construction the sheet abrasive is held smoothly around sleeve S and relative motion between 'abrasive and sleeve prevented.

Preferably, the ends of the collars 21 and 22 which contact with the sleeve S are countersunk to provide a bevelled depression, as shown. The ends of the sleeve may also be bevelled, as depicted.

Practically, it makes no difference which of the cooperating portions, sleeve, ribs, or mandrel, are tapered. Any two of these said members in contact may be tapered, the result being the same in any case, namely, that relative axial movement between the sleeve and the mandrel will cause a change in the diameter of the sleeve. Such relative movement with the cooperating tapers involved gives the desired tautness to the abrasive sheet.

What is claimed is:

1. An abrading tool comprising an arbor, said arbor forming a tapering mandrel, said mandrel having-a spiral groove therein, a sleeve disposed over thearbor and having spaced longitudinally extending ribs on its internal walls which taper from one end of the sleeve to the other bearing on the mandrel portion, an abrading cloth, means for anchoring the abrading cloth, and means for expanding the sleeve.

2. An abrading tool comprising an arbor having plain end parts with one part longer than the other, a threaded portion extending inwardly from each plain part, said threaded portions having their threads extending in opposite directions and said portions being of greater diameter than the plain portions, a mandrel portion located between the threaded portions tapering from one end to the other, the large end of the tapered part being located at that end of the device which carries'the long plain part, each end of the tapered portion having bevelled walls sloping outwardfrom one end of the sleeve to the other, with two" of the ribs located at the slit, with the adjacent walls of the said two ribs forming continuations of the walls of the slit, said walls of the slit diverging from the outer periphery of the sleeve, an abrading cloth encircling the sleeve and having its edges passing through the split in the sleeve and into the slots in the tapered part, said sleeve having beveled ends, and nuts on the threaded portions of the arbor having bevelled inner 'ends for engaging the bevelled ends of the sleeves.

3. A precision hole lap comprising a tapered arbor, a threaded post extending from each end of the arbor, a split sleeve surrounding the arbor, tapered keys projecting inwardly from the sleeve and bearing against the arbor, means including a clamping collar at each end of the sleeve, a tapered seat on each of the clamping collars against which the ends of the sleeve rest, said means being screwed onto the threaded posts for adjustment of the clamping collars and a squared shank, formed on one of saidthreaded posts whereby the lap is operated.

4. A precision. hole lap comprising a tapered arbor, a threaded post extending from each end of the arbor and integrally formed therewith, a split sleeve surrounding the arbor, tapered keys projecting inwardly from the sleeve and bearing against the arbor, means including a clamping collar at each end of the sleeve, a tapered seat on each of the clamping collars against which the end of the sleeve rests, a sheet of abrasive .material wrapped around the sleeve, said clamping collars having substantially the same outside diameter as the abrasive sheet, and saidcollars projecting beyond the outer surface of the sleeve whereby a shoulder is provided against which the abrasive sheet rests, said means being threaded on' said posts to efiect adjustment of said clamping collars.

5. An abrading tool comprising an arbor, said, arbor forming a tapering mandrel, said mandrel having a spiral groove therein, a sleeve disposed over the arbor and having spaced longitudinally extending ribs on its internal walls which taper from one end of the sleeve to the other and bearing on the mandrel portion, an abrading cloth, means for anchoring the abrading cloth, and means for expanding the sleeve.

6. An abrading tool comprising an arbor having plain end parts with one part longer than the other, a threaded portion extending inwardly from each plain part, said threaded portions having their threads extending in opposite directions and said portions being of greater diameter than the plain portions, a mandrel portion located between the threaded portions tapering from one endto the other, the large end of the tapered part being located at that end of the device which carries the long plain part, each end of the tapered portion having bevelled walls sloping outwardly, and said tapered part having a spiral groove therein and a pair of longitudinally extending slots which are convergently arranged with the periphery of the tapered part, a split sleeve having internal longitudinally extending ribs thereon for engaging the tapered part, said sleeve being of uniform thickness and. the ribs tapering from one end of the sleeve to the other, with two of the ribs located at the slit, with the adjacent walls of the said two ribs forming continuations of the walls of the slit, said walls of the slit diverging from the outer periphery of the sleeve, anabrading cloth encircling the sleeve and having its edges passing through the split in the sleeve and into the slots inthe tapered part, said sleeve having bevelled, ends, and nuts on the threaded portions of the arbor having bevelled inner ends for engaging the bevelled ends of the sleeves.

7. A precision hole lap comprising a tapered arbor, a threaded post extending from each end of the arbor, a split sleeve surrounding the arbor, tapered keys projecting inwardly from the sleeve and bearing against the arbor, means including a clamping collar at each end of the sleeve, a tapered seat on eac against which-the ends of the sleeve rest, said means'being screwed onto the threaded posts for of the clamping collars 8. A precision hole lap comprising a tapered arbor, a threaded post extending from each end of the arbor and integrally formed therewith, a

split sleeve surrounding the arbor, tapered keys projecting inwardly from the sleeve and bearingagainst the arbor, means including a clamping collar at each end of the sleeve a tapered seat on each of the clamping collars against. which the end of the sleeve rests, a sheet of abrasive material wrapped around the sleeve, said clamping collars having substantially the same outside diameter as the abrasive sheet, and saidcollars projecting beyond the outer surface of the sleeve whereby a shoulder is provided against which the abrasive sheet rests, said means beingthreaded on said posts to eflect adjustment of said clamping collars. I

9. An abrasive tool comprising a mandrel, a sleeve encircling said mandrel, and having 9. ion-,- gitudinal "slot therein, circumferentially spaced ribs disposed between said mandrel and the said sleeve, said ribs and the co-engaging member being complementarily tapered, means for adjustably moving said sleeve axially relatively to said mandrel, a flexible abrasive sheet disposed about the; sleeve, and means for holding the lon gitudinal edges of said flexible abrasive sheet adjustment of the clamping collars and a squarech when encircling said sleeve.

shank formed on one of said threaded posts whereby the lap is operated. 

